1. Field of the Invention
The invention relates to a rectangular tray for packing and conveying spheroidal fruit, more particularly for separating layers of fruit lying on top of one another.
Such trays must generally be as thin as possible and be as light as possible, and must possess a certain degree of elastic resilience in order to withstand specified pressures in order to avoid damaging the fruit. Accordingly such trays are usually made, for example, of relatively thin-walled foam plastic or paper or cellulose material. At the same time, however, the trays must also be sufficiently stiff so that when a tray which is fully loaded with fruit is gripped in the area of two opposite peripheral edges, for example during loading, and lifted and moved no excessive bending of the tray occurs, particularly to avoid risk of breaking or kinking. The combination of stiffness and low weight, low thickness of the tray, and desired elastic resilience is generally achieved with the use of stiffening channels recessed in the tray.
2. Description of the Prior Art
In known trays of this type the stiffening channels usually extend parallel to one peripheral edge of the tray. As a result, the tray easily bends, thus forming continuous rupture or buckling lines, particularly if the tray is gripped in the area of the two sides of the tray which run parallel to the direction of the stiffening channels and is lifted up. In this known arrangement resistance to bending occurs only in relation to one of the two mutually perpendicular axes of the tray extending parallel to the sides of the tray. That is to say, the tray is strengthened only against bending about the central axis of the tray which is perpendicular to the stiffening channel. As regards the other central axis extending parallel to the said stiffening channel, the risk of rupture and buckling of the tray is even increased by the presence of the stiffening channel. This risk of rupture and buckling is specially high with trays made of foamed polystyrene since this type of plastics material ages relatively quickly and becomes brittle.
It is the object of the invention to eliminate the disadvantages of known designs of tray and to produce a tray for packing and conveying spheroidal fruit in which the stiffening beads produce an increased resistance to bending of the tray about each of the two mutually perpendicular central axes of the tray extending parallel to the sides of the tray.